hi again @Quantice ,
Turns out the currency symbol in the prescription will not be translated either. So, I made a quick fix for it to use the Currency Designator setting that @growlingflea pointed out.
Here are the code changes (minimal, and you likely can make those edits by hand in your code), which I will bring into the development codebase very soon (so fix will be in OpenEMR version 5.0.2).
fix to use gbl currency symbol in rx when dispensing module on by bradymiller · Pull Request #1977 · openemr/openemr · GitHub
-brady